Die for pipe tongs and method of making same



Sept 9, 1952 N. J. BARNARD 2,609,720

DIE FOR PIPE TONGS AND METHOD OF MAKING SAME Filed OCT.. 19, 1951 INVENTOR.

ATTORNEYS.

Patented Sept. 9, 195,2

DIE FOR PIPE TONGS AND METHOD OF MAKING SAME Norval J. Barnard, Oklahoma City, Okla., as-

signer, by mesne assignments, to Charles C.

Weiss, Oklahoma City, Okla.

'Application october 19, 1951, serial No. 252,173

s claims. (c1. :i1- 186) f I 'This invention relates to jaw face inserts, commonly known in well drilling parlance as dies, for `use in various gripping devices such as tongs for gripping drill pipe and preventing slipping of the pipe when unthreading or breaking out drill Y pipe joints incidental to rotary drilling practices.

D ies of this character comprise toothed metal bars that are retained in groove-like seats within "the gripping device and to effect proper grip of such dies, the teeth must be sufficiently hard to penetrate the surface `oi" the drill pipe or object to be gripped thereby. The dies are applied and removed from their groove-like seats by driving them into and out of position with a hammer, withl the blows beingstruck vagainst an end of the die. K p

`It is obvious that due tothe hardness of the teeth the bars are very brittle so that small particleslbreak ofi and fly away with considerable velocity. when the `diesare struck with the hammer. Such flying particles are extremely hazardous because theyy areapt to strike the eye or other vulnerable part of the wielder of the hammer or nearby persons. l ,x

Insurance companies have long experienced this hazard and teach the use of goggles when driving in the dies, but tool dressers seldom go to this trouble with the result that many injuries occur.. The possibility of injury may be realized "when it is considered that as many as a gross of dies may beused in' the" course of drilling a);

vsingle, well..

` l "It is therefore the principal object of thezinvention to avoid'this'h'azard' by providing a die with a hard exterior surface and a relatively soft cen-f tral core extending through the ends of the die-k to provide relatively soft unbreakable portions for receiving the impact of a hammer when the die is driven into and removed from its seat in the jaw of a tong head.

It is also an object of the invention to provide a simple and inexpensive method for forming the die to provide the hardened exterior surface and the soft interior core exposed at ends of the die.

In accomplishing these and other objects of the invention hereinafter pointed out, I have provided improved structure, the preferred form of which is illustrated in the accompanying drawing, wherein:

Fig. 1 is a perspective view of the jaw of a drill pipe tong and showing a die being driven into the groove-like seat of the Jaw.

Fig. 2 is a plan view of the jaw showing the die in place and particularly illustrating the cross-sectional shape of the die seat and the close t of the die therein.

, 2 y Fig. 3 is a central longitudinal section through `a die constructed in accordance with the present invention.

Fig. 4 is an enlarged perspective view of the die. Figs. 5 to 8 are sections through one end of the die showing different steps involved in the construction thereof.

Referring more in detail to the drawings:

I designates a jaw of a conventional tongA head (not shown) which is used for gripping, for example, a drill pipe as when unthreading and breaking out drill pipe joints on pulling the drill pipe from a `borehole in the rotarydrilling wells. VIn order to enhance gripping action ofthe jaws,

the jaws are provided with a.die2 including-a har-like body A3 formed of metaly andhaving tapered sides 4`-5,`fa'front gripping face'-G provided with a plurality of teeth 1, and a back face -8 that joins with the side edges 4 and 5 onacute angles f asbest shown inFig. 6.

The die substantially correspondsA .in lengt with the depthof the jaw and is retained therein by means of ardriving fit within a groove Shaving undercut sides II] and Il and a flat bottom face I2 joining therewith at angles corresponding with the angles between the back and side edges `of the die.`

The cross section of the die and its groove-.like ``se`at are therefore of substantially dovetail shape so that the side edges 4 and 5 ofthe die closely `engage the corresponding sides I0 and IIof the groove for Wedging the back face `8 ofthe die against the bottom face I2.

As above mentioned, the dies are `applied by inserting one end thereof within the upper open end of the groove 9 and driving the die into the groove by striking the opposite end with a hammer I3 as shown in Fig. 1. In order to effect indentation of the teeth within the surfaces of an object to be gripped by the die, for example, the

drill pipe, the teeth of the die must have a relatively high degree of hardness.

Heretofore, such dies have such hardness extending through the metal and the ends thereof are so hard and brittle that hammer blows chip off particles which fiy Vin various directions so that they are extremely hazardous to any person within the vicinity of the work.

In overcoming this hazard, I form the die of uniformly soft metal capable of being heat to lform an exterior shell portion I4 as shown in Fig. 6 which has the required degree of hardness and a core I5 sufficiently soft tofprovide the required toughness and strength for the die. When thus formed the hardened portion extends across the ends of the die as shown at I5 in Fig. 6. The ends are then removed as by grinding to expose ends I5. Vof `the core I5 as shown in Fig. 7. The edges I'I at the ends of the die are beveled or otherwise formed as shown at I8 in Fig. 8 so that the core portion I5 is completely exposed and projects beyond the hardened areas at the surrounding side faces of the die so that When the die is driven into or out of position within the jaw of the die, the hammer contacts the relatively soft projecting ends of the core Without danger of chipping off any particles that are hazardous to `persons in the vicinity of the Work.

In applying a die constructed as described, one end of the die is placed Within the groove 9 and the blows of the hammer I3 are applied to the Vexposed ends of the relativelysoft core I5 at the other end `of the die to drive the die intoits seat. vSince the end surface o f the die is spaced from the exterior hardened surface by the formation of the end edges, the hammer does not make contact with any hardened surface of the die. 'Iherefore,A the die may be safely driven into position or removed by means of a hammer. What I claim and desire to secure by Letters Patent is:

l.. A die of the character described including a bar-like body portion having a relatively hard toothed gripping face and a relatively soft core and substantially-hard side surfaces surroundingV the core with the ends of the core being exposed and projecting beyond. the hardened side surfaces of the die.

2.,.A, heat treated die Vof the character described including a metal'body having arela- VAtively soft core and kexterior 'side portions'k sur- ,3. A die of the characterdescribed including a body portion having a face provided with a plurality of teeth, a substantially hat back face, and` tapered side faces, all of said faces being relatively hard and surrounding a softer core ,with the ends of the core being exposed and pro- ;iecting beyond the hardened side faces of the die.

4. A die of the character described including a metal body having a relatively soft core and substantially hard side portions surrounding the core with an end of the core being exposed and projecting beyond the hardened side portions of the die, said projecting end of the core being beveled toward the hard side portions.

r5. A die of the character described including a body portion having a face provided with a lplurality of teeth, a substantially flat back face, and tapered side faces,. all of said faces being relatively hard and surrounding a softer core with the ends of the core being exposed'and projecting beyondthe hardened side faces of the die, sai d ends of the core being beveled outwardly toward said hard faces.

6. The method of forming a die of the character described including shaping a bar of metal to the form of a die, hardening face portions of the die to provide relatively hard exterior faces, and removing the hardened portions from yan end of the die to expose relatively soft metal at theend of the die.

l'7. The method of forming a die `vincluding shaping a bar of metal to form the die, forming teeth on one surface of the die, heat Ltreating the die to provide relatively hard teeth and exteriorsurfaces, and grinding off ends of the die to expose relatively soft interior portions Yat the ends of the die.

8. The method of forming' va die including shaping a bar of metal to forni the general shape of the die, forming teeth on `onefsurfae of the die, heat treating the die to provide rela'- tively hard exterior surfaces, removing `'theliard exterior surfaces from ends of the die to lexpose relatively ,soft interior portions at the ends of the die, and removing the edges of the hardened side portions of the die surrounding the exposed soft end portions.

NORVAL J B ARNARD.

REFERENCES CITED The following references are of record .in the `file of this patent:

. UNITED STATES PATENTS Number Name Datea 1,844,616 Whitc'n 'Feb. '9, 19312 1,906,696 Lynch i vivray.2,1933 2,187,956 Tow.' Jan. '23, T1940 2,374,192 Godfrey Apr. 24,1946 `2,406,620 vvnscn nur. '27, 11946 2,517,366 

